1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ST1232 Touchscreen Controller Driver
4  *
5  * Copyright (C) 2010 Renesas Solutions Corp.
6  *	Tony SIM <chinyeow.sim.xt@renesas.com>
7  *
8  * Using code from:
9  *  - android.git.kernel.org: projects/kernel/common.git: synaptics_i2c_rmi.c
10  *	Copyright (C) 2007 Google, Inc.
11  */
12 
13 #include <linux/delay.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/i2c.h>
16 #include <linux/input.h>
17 #include <linux/interrupt.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/pm_qos.h>
21 #include <linux/slab.h>
22 #include <linux/types.h>
23 #include <linux/input/touchscreen.h>
24 
25 #define ST1232_TS_NAME	"st1232-ts"
26 #define ST1633_TS_NAME	"st1633-ts"
27 
28 struct st1232_ts_finger {
29 	u16 x;
30 	u16 y;
31 	u8 t;
32 	bool is_valid;
33 };
34 
35 struct st_chip_info {
36 	bool	have_z;
37 	u16	max_x;
38 	u16	max_y;
39 	u16	max_area;
40 	u16	max_fingers;
41 	u8	start_reg;
42 };
43 
44 struct st1232_ts_data {
45 	struct i2c_client *client;
46 	struct input_dev *input_dev;
47 	struct touchscreen_properties prop;
48 	struct dev_pm_qos_request low_latency_req;
49 	struct gpio_desc *reset_gpio;
50 	const struct st_chip_info *chip_info;
51 	int read_buf_len;
52 	u8 *read_buf;
53 	struct st1232_ts_finger *finger;
54 };
55 
56 static int st1232_ts_read_data(struct st1232_ts_data *ts)
57 {
58 	struct st1232_ts_finger *finger = ts->finger;
59 	struct i2c_client *client = ts->client;
60 	struct i2c_msg msg[2];
61 	int error;
62 	int i, y;
63 	u8 start_reg = ts->chip_info->start_reg;
64 	u8 *buf = ts->read_buf;
65 
66 	/* read touchscreen data */
67 	msg[0].addr = client->addr;
68 	msg[0].flags = 0;
69 	msg[0].len = 1;
70 	msg[0].buf = &start_reg;
71 
72 	msg[1].addr = ts->client->addr;
73 	msg[1].flags = I2C_M_RD;
74 	msg[1].len = ts->read_buf_len;
75 	msg[1].buf = buf;
76 
77 	error = i2c_transfer(client->adapter, msg, 2);
78 	if (error < 0)
79 		return error;
80 
81 	for (i = 0, y = 0; i < ts->chip_info->max_fingers; i++, y += 3) {
82 		finger[i].is_valid = buf[i + y] >> 7;
83 		if (finger[i].is_valid) {
84 			finger[i].x = ((buf[i + y] & 0x0070) << 4) | buf[i + 1];
85 			finger[i].y = ((buf[i + y] & 0x0007) << 8) | buf[i + 2];
86 
87 			/* st1232 includes a z-axis / touch strength */
88 			if (ts->chip_info->have_z)
89 				finger[i].t = buf[i + 6];
90 		}
91 	}
92 
93 	return 0;
94 }
95 
96 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
97 {
98 	struct st1232_ts_data *ts = dev_id;
99 	struct st1232_ts_finger *finger = ts->finger;
100 	struct input_dev *input_dev = ts->input_dev;
101 	int count = 0;
102 	int i, ret;
103 
104 	ret = st1232_ts_read_data(ts);
105 	if (ret < 0)
106 		goto end;
107 
108 	/* multi touch protocol */
109 	for (i = 0; i < ts->chip_info->max_fingers; i++) {
110 		if (!finger[i].is_valid)
111 			continue;
112 
113 		if (ts->chip_info->have_z)
114 			input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR,
115 					 finger[i].t);
116 
117 		touchscreen_report_pos(input_dev, &ts->prop,
118 					finger[i].x, finger[i].y, true);
119 		input_mt_sync(input_dev);
120 		count++;
121 	}
122 
123 	/* SYN_MT_REPORT only if no contact */
124 	if (!count) {
125 		input_mt_sync(input_dev);
126 		if (ts->low_latency_req.dev) {
127 			dev_pm_qos_remove_request(&ts->low_latency_req);
128 			ts->low_latency_req.dev = NULL;
129 		}
130 	} else if (!ts->low_latency_req.dev) {
131 		/* First contact, request 100 us latency. */
132 		dev_pm_qos_add_ancestor_request(&ts->client->dev,
133 						&ts->low_latency_req,
134 						DEV_PM_QOS_RESUME_LATENCY, 100);
135 	}
136 
137 	/* SYN_REPORT */
138 	input_sync(input_dev);
139 
140 end:
141 	return IRQ_HANDLED;
142 }
143 
144 static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
145 {
146 	if (ts->reset_gpio)
147 		gpiod_set_value_cansleep(ts->reset_gpio, !poweron);
148 }
149 
150 static const struct st_chip_info st1232_chip_info = {
151 	.have_z		= true,
152 	.max_x		= 0x31f, /* 800 - 1 */
153 	.max_y		= 0x1df, /* 480 -1 */
154 	.max_area	= 0xff,
155 	.max_fingers	= 2,
156 	.start_reg	= 0x12,
157 };
158 
159 static const struct st_chip_info st1633_chip_info = {
160 	.have_z		= false,
161 	.max_x		= 0x13f, /* 320 - 1 */
162 	.max_y		= 0x1df, /* 480 -1 */
163 	.max_area	= 0x00,
164 	.max_fingers	= 5,
165 	.start_reg	= 0x12,
166 };
167 
168 static int st1232_ts_probe(struct i2c_client *client,
169 			   const struct i2c_device_id *id)
170 {
171 	const struct st_chip_info *match;
172 	struct st1232_ts_data *ts;
173 	struct st1232_ts_finger *finger;
174 	struct input_dev *input_dev;
175 	int error;
176 
177 	match = device_get_match_data(&client->dev);
178 	if (!match && id)
179 		match = (const void *)id->driver_data;
180 	if (!match) {
181 		dev_err(&client->dev, "unknown device model\n");
182 		return -ENODEV;
183 	}
184 
185 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
186 		dev_err(&client->dev, "need I2C_FUNC_I2C\n");
187 		return -EIO;
188 	}
189 
190 	if (!client->irq) {
191 		dev_err(&client->dev, "no IRQ?\n");
192 		return -EINVAL;
193 	}
194 
195 	ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
196 	if (!ts)
197 		return -ENOMEM;
198 
199 	ts->chip_info = match;
200 	ts->finger = devm_kcalloc(&client->dev,
201 				  ts->chip_info->max_fingers, sizeof(*finger),
202 				  GFP_KERNEL);
203 	if (!ts->finger)
204 		return -ENOMEM;
205 
206 	/* allocate a buffer according to the number of registers to read */
207 	ts->read_buf_len = ts->chip_info->max_fingers * 4;
208 	ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL);
209 	if (!ts->read_buf)
210 		return -ENOMEM;
211 
212 	input_dev = devm_input_allocate_device(&client->dev);
213 	if (!input_dev)
214 		return -ENOMEM;
215 
216 	ts->client = client;
217 	ts->input_dev = input_dev;
218 
219 	ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL,
220 						 GPIOD_OUT_HIGH);
221 	if (IS_ERR(ts->reset_gpio)) {
222 		error = PTR_ERR(ts->reset_gpio);
223 		dev_err(&client->dev, "Unable to request GPIO pin: %d.\n",
224 			error);
225 		return error;
226 	}
227 
228 	st1232_ts_power(ts, true);
229 
230 	input_dev->name = "st1232-touchscreen";
231 	input_dev->id.bustype = BUS_I2C;
232 	input_dev->dev.parent = &client->dev;
233 
234 	__set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
235 	__set_bit(EV_SYN, input_dev->evbit);
236 	__set_bit(EV_KEY, input_dev->evbit);
237 	__set_bit(EV_ABS, input_dev->evbit);
238 
239 	if (ts->chip_info->have_z)
240 		input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
241 				     ts->chip_info->max_area, 0, 0);
242 
243 	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
244 			     0, ts->chip_info->max_x, 0, 0);
245 	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
246 			     0, ts->chip_info->max_y, 0, 0);
247 
248 	touchscreen_parse_properties(input_dev, true, &ts->prop);
249 
250 	error = devm_request_threaded_irq(&client->dev, client->irq,
251 					  NULL, st1232_ts_irq_handler,
252 					  IRQF_ONESHOT,
253 					  client->name, ts);
254 	if (error) {
255 		dev_err(&client->dev, "Failed to register interrupt\n");
256 		return error;
257 	}
258 
259 	error = input_register_device(ts->input_dev);
260 	if (error) {
261 		dev_err(&client->dev, "Unable to register %s input device\n",
262 			input_dev->name);
263 		return error;
264 	}
265 
266 	i2c_set_clientdata(client, ts);
267 	device_init_wakeup(&client->dev, 1);
268 
269 	return 0;
270 }
271 
272 static int st1232_ts_remove(struct i2c_client *client)
273 {
274 	struct st1232_ts_data *ts = i2c_get_clientdata(client);
275 
276 	st1232_ts_power(ts, false);
277 
278 	return 0;
279 }
280 
281 static int __maybe_unused st1232_ts_suspend(struct device *dev)
282 {
283 	struct i2c_client *client = to_i2c_client(dev);
284 	struct st1232_ts_data *ts = i2c_get_clientdata(client);
285 
286 	if (device_may_wakeup(&client->dev)) {
287 		enable_irq_wake(client->irq);
288 	} else {
289 		disable_irq(client->irq);
290 		st1232_ts_power(ts, false);
291 	}
292 
293 	return 0;
294 }
295 
296 static int __maybe_unused st1232_ts_resume(struct device *dev)
297 {
298 	struct i2c_client *client = to_i2c_client(dev);
299 	struct st1232_ts_data *ts = i2c_get_clientdata(client);
300 
301 	if (device_may_wakeup(&client->dev)) {
302 		disable_irq_wake(client->irq);
303 	} else {
304 		st1232_ts_power(ts, true);
305 		enable_irq(client->irq);
306 	}
307 
308 	return 0;
309 }
310 
311 static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
312 			 st1232_ts_suspend, st1232_ts_resume);
313 
314 static const struct i2c_device_id st1232_ts_id[] = {
315 	{ ST1232_TS_NAME, (unsigned long)&st1232_chip_info },
316 	{ ST1633_TS_NAME, (unsigned long)&st1633_chip_info },
317 	{ }
318 };
319 MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
320 
321 static const struct of_device_id st1232_ts_dt_ids[] = {
322 	{ .compatible = "sitronix,st1232", .data = &st1232_chip_info },
323 	{ .compatible = "sitronix,st1633", .data = &st1633_chip_info },
324 	{ }
325 };
326 MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
327 
328 static struct i2c_driver st1232_ts_driver = {
329 	.probe		= st1232_ts_probe,
330 	.remove		= st1232_ts_remove,
331 	.id_table	= st1232_ts_id,
332 	.driver = {
333 		.name	= ST1232_TS_NAME,
334 		.of_match_table = st1232_ts_dt_ids,
335 		.pm	= &st1232_ts_pm_ops,
336 	},
337 };
338 
339 module_i2c_driver(st1232_ts_driver);
340 
341 MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
342 MODULE_AUTHOR("Martin Kepplinger <martin.kepplinger@ginzinger.com>");
343 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
344 MODULE_LICENSE("GPL v2");
345